Edge fires drive the shape and stability of tropical forests

The shape of the areas we protect may be more important than the size, too thin exposes them to death by fire, too round inhibits growth

In tropical regions, fires that start in grassland typically burn only the edges of forested regions, but do not spread within the forest. This behaviour starkly contrasts with wildfires in temperate forests, where the fire spreads readily through the trees via local ignition of neighbouring trees.

Using our spatial model, we showed that commonly observed ‘edge effects’ drive the stability and fate of individual forest patches. Importantly, the two competing processes of exposure to fire and propagative growth do not balance because of their very different time scales. For a forest of a given size, having a large perimeter means that it is more likely to be exposed to fire before it receives any benefit from increased tree cover due to propagative growth. Contrarily, if too dense, a forest will not grow sufficiently quickly to offset its exposure to fire, which will lead to an increase in perimeter by encroachment of grassland at the forest edges. The forests that do survive are those that end up with intermediate shapes to ensure enough perimeter growth to offset their exposure to fire.

read the paper

Global forest change map and data

Note:
Wiley Publishing has made a large amount of science available online:
Wiley Online Library, Ecology Letters

UGA researchers develop new method to improve crops


A team of University of Georgia researchers has developed a new way to breed plants with better traits. By introducing a human protein into the model plant species Arabidopsis thaliana, researchers found that they could selectively activate silenced genes already present within the plant.

Using this method to increase diversity among plant populations could serve to create varieties that are able to withstand drought or disease in crops or other plant populations, and the researchers have already begun testing the technique on maize, soy and rice.

They published their findings in Nature Communications.

The research project was led by Lexiang Ji, a doctoral student in bioinformatics, and William Jordan, a doctoral student in genetics. The new method they explored, known as epimutagenesis, will make it possible to breed diverse plants in a way that isn’t possible with traditional techniques.

“In the past this has been done with traditional breeding. You take a plant, breed it with another plant that has another characteristic you want to create another plant,” said Jordan. “The problem with that is getting an individual that has all of the characteristics you want and none of the characteristics that you don’t want. It’s kind of difficult. With our new technique, you can modify how the genes are turned on and off in that plant without having to introduce a whole other set of genes from another parent.”

Paper
TET-mediated epimutagenesis of the Arabidopsis thaliana methylome

Scientists find how and why behind Saxifraga’s silver crust



Silver linings – new research reveals the science behind the Saxifrage’s silver-white crust


Scientists at Sainsbury Laboratory Cambridge University have found that the mineral vaterite, a form (polymorph) of calcium carbonate, is a dominant component of the protective silvery-white crust that forms on the leaves of a number of alpine plants, which are part of the Garden’s national collection of European Saxifraga species.

Naturally occurring vaterite is rarely found on Earth. Small amounts of vaterite crystals have been found in some sea and freshwater crustaceans, bird eggs, the inner ears of salmon, meteorites and rocks. This is the first time that the rare and unstable mineral has been found in such a large quantity and the first time it has been found to be associated with plants.….

Paper
Hydathode pit development in the alpine plant Saxifraga cochlearis

Have blue flowers arrived?

For centuries breeders have sought to make true blue flowers, yet there is no true blue pigment in plants.


(Image source @ScienceAdvances on Twitter)

In nature, blue is much rarer than you might think. Sure, the sky is blue when the weather’s nice, and so is the ocean. But the vast majority of plants and animals are incapable of making blue pigment. Brilliantly-colored peacocks appear blue not because their feathers are colored that way, but because of how they reflect light. Less than 10 percent of the world’s 280,000 flowering plants produce blue flowers, which may be why they’re often a symbol of the unattainable in folklore and literature.

Suntory Global Innovation Center, Blue Roses

Scientists genetically engineer the world’s first blue chrysanthemum

Generation of blue chrysanthemums by anthocyanin B-ring hydroxylation and glucosylation and its coloration mechanism

Tomato plants turn munching caterpillars into cannibals



It turns out that cannibalism is widespread among the insects that otherwise spend their time munching on plants. “It often starts with one caterpillar biting another one in the rear, which then oozes,” said University of Wisconsin–Madison’s John Orrock in a press release describing his work. “And it goes downhill from there. At the end of the day, somebody gets eaten.”

It’s considered a stress response to a lack of food. What surprised Orrock was that this behavior sometimes took place on plants. You know, the things these caterpillars are supposed to be eating. If the food’s right there, why would these insects be turning on each other?

It all comes back to the chemicals a plant releases to say “watch out, I’m being eaten.” This is typically some chemical relative of jasmonic acid, a regulator of plant stress responses. While jasmonic acid can be used to coordinate a plant’s own response to stress, it also gets out into the environment and alerts other plants that something stressful is going on.

Paper:
Induced defences in plants reduce herbivory by increasing cannibalism

More info:
Jasmonic acid distribution and action in plants: Regulation during development and response to biotic and abiotic stress

Growing plants in vinegar could help them survive drought



It sounds—and sort of looks—like something out of a middle school science experiment, but according to a study done at RIKEN Center for Sustainable Resource Science in Japan, a new and simple way to increase a plant’s drought tolerance is to grow it in vinegar……

Acetate-mediated novel survival strategy against drought in plants